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Which tests performed on I.M.?
Voltage ratio test
Slip test
Locked rotar test
All of above
All of above
Quick Summary: To ensure the performance and reliability of Induction Motors (I.M.), several standard tests are performed during installation, commissioning, and maintenance. These include the Voltage Ratio test (for wound rotor machines), Slip test, and Locked Rotor test to determine machine parameters and operating characteristics.
To ensure the performance and reliability of Induction Motors (I.M.), several standard tests are performed during installation, commissioning, and maintenance. These include the Voltage Ratio test (for wound rotor machines), Slip test, and Locked Rotor test to determine machine parameters and operating characteristics.
s=nsns−nr — Slip calculation formula
Isc=Req2+Xeq2Vsc — Locked rotor current relationship
The Locked Rotor test (equivalent to a short-circuit test in transformers) is used to determine equivalent resistance and leakage reactance. The Slip test is used to determine the d-axis and q-axis reactances of synchronous machines or induction behavior, while the Voltage Ratio test verifies the turns ratio in slip-ring induction motors.
Locked Rotor test determines short-circuit parameters under standstill conditions.
Voltage ratio test is essential for wound rotor motors to check insulation and turn symmetry.
Slip test is typically used to identify motor speed characteristics at various load conditions.
All these tests are part of the BIS/IEC testing standards for electrical machines.
Ensures operational safety
Provides accurate performance parameters
Requires high power testing equipment
Time-consuming during field commissioning
Manufacturing quality control
Post-repair maintenance validation
These tests are performed to verify the nameplate specifications against field performance.
Option D is chosen because all listed items are standard procedures in I.M. diagnostics.
D is correct — The Voltage ratio test, Slip test, and Locked rotor test are all standard diagnostic procedures used for evaluating Induction Motor performance.
Remember that the Locked Rotor test corresponds to the Short Circuit test in transformers, and the No-load test corresponds to the Open Circuit test.